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28 fore and aft of the ships: _ Suppositig the deviation on east was 20 degrees, the de- - yiation due to this same cause would be 19.6° on E by N; 185° on ENE; 16.6° on NE by E; 14.1° on NE; 11.1° on NE by N; 2.7° on NNE; 3.9° on.N by E and nothing on N. Just draw this out and try it for yourself. The Traverse Ta- bles are handy for this purpose since you can. find by mere inspection the whole 'thing in a minute or two. Hf the Trav- erse Tables are used (one would hardly think of getting along without them, but I am showing what can be done without them) the rule is simply this: the distance column for the amount of your deviation on N. or S. for the point of the compass you desire to find the ef- fects of this deviation and pick it out in the Lat. column. With the deviation on either E or W do the same thing only you will find it now in the Dep. column. A little study and practice will make this all very clear. If it is now desired to know the total effect of the semicir- cular deviation on any given point add the two deviations as found for the point 'and you have it. For. example: The total semicircular deviation on NE by E is 5.6° + 16.6° =22.2°. With the fore- going information it becomes a very easy matter to draw both™ parts of the semi- circular deviation to a curve or the whole of it, just as you please. ~The quadrantal deviation has its max- imum amount on the intercardinal points © and dwindles away to nothing on the cardinal points. ° The quadrantal devia- tion changes twice as rapidly as does the semicircular deviation. Illustrating this change by means of the right triangle 'proceed thus: First establish the point of the compass you desire the quadran- tal deviation for, and determine how far it ig from the nearest cardinal point. Double this angle and draw its line as a course of a length equal to the quadran- tal deviation on an intercardinal point. Next draw a perpendicular and base to 'conform to the angle line (hypotenuse) drawn. The length of the base line will give you the required deviation. Exam- ple: The quadrantal deviation on NE is 6° what it will be on NE. by E? NE. by E is 3 points from East, and twice 3 is 6, or 6 points; ENE is a 6-point course, so we. draw an ENE line 6 parts long, and the departure line drawn to conform with it will be the amount of the quadrantal deviation on NE by E if it is 6 degrees on NE. The Dev. is 5.5". It. will also be the quadrantal deviation sen NE by N, since .NE by N jis also 3 points from a cardinal po:nt. NNE:and ENE, each being 2 points from a cardinal point, and twice this angle will make 4 points or 45 degrees. So draw a 45 degree angle 6 parts long and draw the departure line to conform to it and Seek in - For' THE Marine REVIEW its length will give the quadrantal devi- ation for-NNE and ENE. It will be found to be+42 degrees. On N by E and E by N it will be 2.3 degrees. See Figs: 6 and 7. Note.--A protractor may be used for 'laying off the angles employing a scale of equal parts for measuring the sides. Tt will: also be found hae venient to work it on.a-c allel ruler and the chart compass. convenient scale will answer the purpose so long as the same scale is used for measuring all the sides. It must be re- membered that only the direction of the hypotenuse and its length is required, for ifa.truly perpendicular line is drawn up- ward from its starting pointing and a true horizontal line is drawn from the end of the hypotenuse to intersect with this perpendicular line so as to form a truly right angle, the sides will be a pre- cise proportion af the hypotenuse. Although the. quadrantal deviation is rarely large in amount like the semi- * PIN NDE ge FIG, '7, circular deviation, it is more embarrass- ing than a semicircular deviation of the same. amount, since it changes twice as rapidly. , The true significance of this will be seen when it is explained that a quadrantal deviation of 10° implies a rapid change in the deviation of the com- pass, amounting to so much as a half point with so small a change as a point and a half in the ship's course, from one side to the other of the four cardinal courses. Peter C. Peterson, watchman on the stéamer Superior City, is considered one*of the most athletic men on the lakés'although he is sixty years of age. He can balance a broom. at arm's length with two fingers, and can hold a chair out in the same way with the same number of fingers. Rese gusas, LONDON'S SEVEN-YEAR'S CRUISE. Jack London, the noted author and story writer, vefy recently sailed from San Francisco on his new, trim, and staunch little sail and steam yacht, the Snark, bound on a seven-year's cruise around the globe. London is accom- panied by his young wife and a crew of four. : The Snark is the aed ae that has, perhaps, ever yet attempted the. circumnavigation of the globe. This yacht is 57 ft. over all; has 15-ft. beam, and 7-ft. draught. Completed; fully the Snark equipped, provisioned, etc., cost about $25,000. The Snark proceeds. direct to Hono- nd from thence to the remote eas, visiting in turn China, Ja- stralia, New Zealand, the Mar- Polynesia, India, and so on THE SNARK. ' around the navigable globe. London also proposes, if possible, to ascend the Yang-tse-Kiang, Zambesi, Congo, Nile, Amazon, and other great streams. In round numbers, London expects his protracted voyage will last 2,555 days. Travel, quest of adventure, and to col- lect new material for his prolific pen, are the chief motives prompting the au- thor to make this long and perilous cruise. London is under contract to furnish a series of articles to several large American publications during his pro- tracted voyage. He plans to do syste- matic literary work on the cruise in which he will be efficiently assisted hy Mrs. London, that lady acting as his amanuensis and typewriter. The government tug J. M. Wilson has recently been dry docked at the yard of the 'Moran Co., Seattle, Wash., for painting and slight re- pairs to her hull.